Most of my driving is done in the city and I've averaged 16.8 mpg. We did take a trip to Toronto and on the way back, we decided to see how well it performed at high speeds. At 65 mph, we were getting aprox. 20.2 mpg; 80 mph it was 22 mpg and around 110-115 mpg around 21.6. Odd that I got better mileage at 80 than 65 considering I don't have air suspension which lowers the body at high speeds.

2008 R350 2WD, about 3000miles now and i only really drive in the city. avg 15.6 mpg. i have a heavy foot and drive it in S mode. on the rare occasion we take it on the highway, it avg over 22 mpg easy. i expected better.

I have driven the R320 cdi for a year now. On the highway it excels at mpg - 25-26 while loaded down (including a roof cargo box) and going quite fast. I don't remember seeing anything below 20. Around town - in the C mode I get 21-22. I have trouble seeing out of it while backing, but it's quite the "touring" car.

I have had my 06 for two weeks now, and I'm kind of freaking. I don't drive that much (thank God), but I went from a Chrysler Pacifica (don't laugh, I loved the Pacifica...never a problem) so I was used to that. I never figured out what I was getting in the Pacifica, but it must have been damned good, because I'm a little peeved with the R350 Tank. I thought, because it was very much like the Pacifica (minus the 4-wd), it would be very similar in gas mileage. Gulp (no pun intended). I was a little taken aback. I have had to fill up twice since getting it. As I said, it's only been two weeks. I filled the Pacifica up twice a month, if I drove a lot. So, it's a huge diff. I am bummed out.

I'm serious...around town drive in C mode. Only drive in S mode on the highway or when you know you'll be rocking steady at 55 or above for awhile. You'll see a marked improvement in gas mileage. Try this on a new tank of gas.... and reset all of your counters. You'll see. Don't believe all you read. I know my R320 gets better mileage than a gas model (which is why I bought it) but you can improve your numbers.

I drove my 320 from MD to FL with a loaded cargo box on top, and filled to the brim inside - going 75-80 and got 25+ mpg. It's a marvel. Around town, stop and go can be down to 20, but average 22.5+ in day-to-day driving.

I've had my 08 R350 for about 14 months mostly driven around town by wife but I was getting approx 17 in town and 22-24 on hwy on the stock tires (Continental Contact). I had to replace those crummy treads after only 15k and a few months ago put on a set of Toyo All Country. Now smoother ride and bump in mpg of about 2 mpg for both in town and on hwy miles.

I have an 2007 R320 and it's gets spectacular fuel mileage for a car it's size. I don't know much about the new diesel engines and what is required with the urea filters, etc. Diesel fuel is running on par with the cost of hightest gas. Diesel's last forever...

FYI for comparison purposes I did some test drives before buying this car and with identical test drive routes i got 23.8mpg in a deisel R320 vs. 17mpg with unleaded gas R350. (about 29% better milage with diesel engine, yet in my area diesel is same price as Premium unleaded and diesel was about 10-12% higher than low grade unleaded. And diesels are "supposed" to last about twice as long as their unleaded counterparts. So, still better value eitherway with diesel.